The 24-year-old Belgian will return to Jose Mourinho's Premier League-leading squad.
Belgium midfielder Eden Hazard has signed a new five-and-a-half year deal with Chelsea, according to BBC Sport.
Hazard has been with the club since the 2012 season and he was happy to finish a deal that would keep him at Stamford Bridge.
"Since I came here in 2012, I have always felt good and the club has been very supportive to me," Hazard said.
"[Chelsea manager Jose Mourinho] has helped me improve a lot, the fans have been fantastic and I have an amazing understanding with my team-mates," he added.
In 36 matches for Chelsea this year, Hazard has scored 13 goals.
He has also made 147 appearances for the Belgium National Team, helping the Blues reach the quarterfinals of the 2014 World Cup in Brazil. Hazard has scored 43 goals for his national squad.
Mourinho was also excited about the signing and spoke highly of the 24-year-old's potential in the future.
He is already a top player and his evolution has been fantastic," Mourinho said. "He is still very young and he can become the best."
In the Premier League this season, Hazard and Chelsea sit atop the table with an 18-5-2 record. With 59 points so far, the team is seven points ahead of second place Manchester City
- Jack Jorgensen